Newly-developed techniques make individual retinal cells of each type accessible under visual control. These will be used to explore in detail, the nature of synaptic communication between retinal cells. The techniques allow individual cells, or pairs of synaptically-related cells to be penetrated, recorded from, and stained with Lucifer yellow during the recording session. Many aspects of retinal function, heretofore accessible only by the most tedious effort, can now be easily explored. We will concentrate on 4 acreas: 1) determination of the postsynaptic effects of each synaptic input to retinal cells, accompanied by an evaluation of mimetic substances, 2) clarification of the time and voltage-dependent properties of each type of retinal cell, 3) exploration of the mechanisms of voltage-controlled modulation of transmitter release from tonically active, steadily depolarized slow-potential cells, and 4) direct measure of communication between individual cells under visual control. Questions to be addressed include: 1) the effect of a single rod or cone upon each type of bipolar cell, and the changes in the strength of that effect with light adaptation and surround antagonism, 2) the effect of a single bipolar cell upon each of the ganglion cell-types, and an evaluation of possible morphological and physiological subtypes of bipolar cell (in addition to the on- and off- types), and 3) the influence of individual horizontal or amacrine cells upon each other, and upon their feed back and feed forward targets. In addition, the technique generates some axon-less receptors and bipolars, and some dendrite-less bipolars. Each is useful for localizing cellular events to cell components. The new techniques liberate the retina from constraints imposed upon the traditional eyecup preparation, and allow detailed neurobiological studies in this intriguing but difficult preparation.